You can create a GST Classification in order to record the tax rate and other details for a category of goods attracting under a specific GST rate. When this classification is used in relevant masters and transactions, the details of goods and services will be automatically captured.

In above image, I have create Inter State sale to E-Commerce consumer and define tax rates thereon, and in below image you can see tax classification of Sale to E-Commerce consumer is appear in tax classification at right side in classification details.

You can create each tax classification which will be applicable according to your accounting method.